Method for determining a parameter of an optical equipment

ABSTRACT

A method for determining a parameter of an optical equipment, including: an optical equipment positioning, during which an optical equipment including a pair of optical lenses mounted on a spectacle frame is positioned in a first position; a portable electronic device positioning, during which a portable electronic device including an image acquisition module is positioned in a second position determined and/or known relatively to the first position to acquire an image of a distant element seen through at least part of the optical lenses of the optical equipment in the first position; a parameter determining, during which at least one optical parameter of the optical equipment is determined based on the image of a distant element seen through at least part of the optical lenses of the optical equipment in the first position.

FIELD OF THE INVENTION

The invention relates to a method for determining a parameter of anoptical equipment, a device for determining at least one parameter of anoptical equipment, a method for ordering a new optical equipment and amethod for providing a new optical equipment to a person.

BACKGROUND OF THE INVENTION

Usually, a person wishing to have an optical equipment goes to see aneye care practitioner.

The eye care practitioner orders the eyewear equipment at an optical labby sending an order request to the optical lab. The order request maycomprise wearer data, for example the wearer's prescription, fittingdata, spectacle frame data, for example the type of spectacle frame thewearer has selected, and lens data, for example the type of optical lensthe wearer has selected.

The determination of the wearer's prescription and fitting data mayrequire carrying out complex and time consuming measurements. Suchmeasurements usually require complex and costing material and qualifiedpersonnel to be carried out.

Such measurements are usually carried out even when the person's opticalneeds have not changed. For example, a person that wants to order a newframe with the same optical lenses than with his/her previous spectaclesmay have to go through the tedious process indicated previously.

The eye care practitioner may use lens mapper and/or lens meter todetermine the optical features of the current optical lenses of theoptical equipment of the person. However, such devices still requiregoing to the eye care practitioner since there are very expensive andrequire qualified person to be used. In other words, the person himselfmay not use such devices to determine the parameters to be included inthe order request. Typically, such devices are not available when aperson wishes to order a new optical equipment over the internet.

Therefore, there is a need to a method and a device that would allow aperson to quickly, easily and at low cost determined optical parametersof his/her current optical equipment.

One object of the present invention is to provide such method.

SUMMARY OF THE INVENTION

To this end, the invention proposes a method for determining a parameterof an optical equipment, the method comprising:

-   -   an optical equipment positioning step, during which an optical        equipment comprising a pair of optical lenses mounted on a        spectacle frame is positioned in a first position,    -   a portable electronic device positioning step, during which a        portable electronic device comprising an image acquisition        module is positioned in a second position determined and/or        known relatively to the first position so as to acquire an image        of a distant element seen through at least part of the optical        lenses of the optical equipment in the first position,    -   a parameter determining step, during which at least one optical        parameter of the optical equipment is determined based on the        image of a distant element seen through at least part of the        optical lenses of the optical equipment in the first position.

Advantageously, the method of the invention allows a person to determineoptical parameters of his/her current optical equipment by simply usinga portable electronic device, such as a smartphone, a tablet computer ora laptop.

According to further embodiments which can be considered alone or incombination:

-   -   the method further comprises a pattern positioning step during        which a pattern is positioned in a third position relative to        the optical equipment so as to allow the portable electronic        device in the second position to acquire an image of the pattern        seen through at least part of the optical lenses of the optical        equipment in the first position; and/or    -   the third position is determined and/or known relatively to the        first and/or second position; and/or    -   the optical parameter is determined by comparing the pattern        with the image of the pattern seen through at least part of the        optical lenses of the optical equipment in the first position;        and/or    -   the method further comprises a position determining step during        which the distance and the relative orientation of the image        acquisition module of the portable electronic device and the        optical equipment are determined; and/or    -   the distance and relative orientation of the image acquisition        module of the portable electronic device and the optical        equipment are determined using at least measuring means of the        portable electronic device; and/or    -   the distance and relative orientation of the image acquisition        module of the portable electronic device and the optical        equipment are determined using at least measuring means        including a printed sheet having specific printed features;        and/or    -   the distance and relative orientation of the image acquisition        module of the portable electronic device and the optical        equipment are determined using a known size element positioned        at the second and/or third positions; and/or    -   the optical parameter of the optical equipment comprises        parameters selected in the list consisting of:        -   the optical power in a visual reference zone of the optical            lenses,        -   the optical cylinder in a visual reference zone of the            optical lenses,        -   the optical cylinder axis in a visual reference zone of the            optical lenses,        -   the optical prism in a visual reference zone of the optical            lenses,        -   the type of optical design of the optical lenses; and/or    -   the method further comprising:        -   a fitting parameter determining step during which at least            one fitting parameter of the optical lenses in the spectacle            frame is determined based on an image of the spectacle frame            acquired by the portable electronic device and the image of            a distant element seen through at least part of the optical            lenses of the optical equipment in the first position,        -   wherein the fitting parameter is determined based on the            position of a reference point of the optical lenses relative            to the spectacle frame.

The invention also relates to a device for determining at least aparameter of an optical equipment comprising a pair of optical lensesmounted on a spectacle frame, the device comprising:

-   -   a receiving element configured to physically receive the optical        equipment in at least a first predetermined position,    -   an acquisition receiving element configured to physically        receive a portable electronic device having an image acquisition        module in at least a second predetermined position relative to        the optical equipment received by the receiving element so as to        acquire an image of a distant element seen through at least part        of the optical lenses of the optical equipment received by the        receiving element.

According to further embodiments which can be considered alone or incombination:

-   -   the device further comprises at least one predetermined pattern        to be used as said distant element; and/or    -   the predetermined pattern is in at least a third predetermined        position relative to the first and second predetermined        positions; and/or    -   the device further comprises means for determining the position        of the distant element relative to the first and/or second        predetermined positions; and/or    -   the device further comprises a light reflecting element        configured to reflect a pattern displayed on a screen of the        portable electronic device so as to provide a distant element to        be acquired by the portable electronic device through at least        part of the optical lenses of the optical equipment received by        the receiving element; and/or    -   the device further comprises a light reflecting element        configured to reflect a pattern displayed on a screen of the        portable electronic device so as to provide a distant element to        be acquired by the portable electronic device through at least        part of the optical lenses of the optical equipment received by        the receiving element, wherein the device is configured so that        the portable electronic device acquires an image of the pattern        deformed twice by the optical equipment, and the portable        electronic device is selected in the list consisting of a        smartphone, a personal digital assistant and a tablet computer.

The invention further relates a method for ordering a new opticalequipment for a user of a first optical equipment, the methodcomprising:

-   -   an optical equipment positioning step, during which the first        optical equipment comprising a first pair of optical lenses        mounted on a first spectacle frame is positioned in a first        position,    -   a portable electronic device positioning step, during which a        portable electronic device comprising an image acquisition        module is positioned in a second position so as to acquire an        image of a distant element seen through at least part of the        optical lenses of the first optical equipment in the first        position,    -   an acquisition step during which at least one image of the        distant element seen through at least part of the optical lenses        of the first optical equipment is acquired,    -   a position adjustment step during which the relative position of        the portable electronic device and the first optical equipment        is adjusted based on an identification of at least part of the        optical equipment and/or the portable electronic device,    -   an ordering step during which an order request for a new optical        equipment is sent to a distant entity, the order request        comprising the at least one image acquired by the portable        electronic device and new optical equipment identification data.

The method may further comprise a parameter determining step, duringwhich at least one optical parameter of the optical equipment isdetermined based on the image of a distant element seen through at leastpart of the optical lenses of the optical equipment in the firstposition.

The method of the invention may further comprise a device providing stepduring which a device according to the invention is provided to positionthe first optical equipment and a portable electronic device.

The invention also relates to a method for providing optical equipmentfor a person, the method comprising:

-   -   an order receiving step during which an order request generated        by a method according to the invention and comprising at least        an image of a predetermined element seen through at least part        of the optical lenses of the first optical equipment of the        person is received,    -   a parameter determining step during which at least one optical        parameter of the optical equipment is determined based on the at        least one received image,    -   an optical equipment providing step during which a new optical        equipment is provided to the person based on the at least one        optical parameter determined during the parameter determining        step.

The invention further relates to a computer program product comprisingone or more stored sequences of instructions that are accessible to aprocessor and which, when executed by the processor, causes theprocessor to carry out at least the steps of the method according to theinvention.

The invention also relates to a computer-readable storage medium havinga program recorded thereon; where the program makes the computer executeat least the steps of the method of the invention.

The invention further relates to a device comprising a processor adaptedto store one or more sequence of instructions and to carry out at leaststeps of the method according to the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described, by way of exampleonly, and with reference to the following drawings in which:

FIG. 1 is a flow chart representing a method for determining a parameterof an optical equipment according to the invention,

FIG. 2 illustrates the positioning a portable electronic device, anoptical equipment and a pattern according to a method of the invention,

FIG. 3 illustrates the orientation of a spectacle frame,

FIG. 4 is a schematic representation of a device according to theinvention,

FIG. 5 is an example of template according to the invention,

FIG. 6 is a flow chart representing an ordering method according to theinvention,

FIG. 7 is a flow chart representing an ordering method according to theinvention,

FIGS. 8 and 9 illustrate examples of devices according to the invention,

FIG. 10 illustrates an implementation of a dimension determining step ofthe invention,

FIG. 11 illustrates an example of a calibration of a laptop screen,

FIGS. 12A and 12B illustrate an implementation of an optical equipmentpositioning step of the invention,

FIGS. 13 A and 13 B illustrate an implementation of a portableelectronic device positioning step of the invention,

FIGS. 14 to 16 illustrate a perspective effect, and

FIGS. 17 and 18 illustrate a method for compensating the perspectiveeffect.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Elements in the figures are illustrated for simplicity and clarity andhave not necessarily been drawn to scale. For example, the dimensions ofsome of the elements in the figure may be exaggerated relative to otherelements to help improve the understanding of the embodiments of thepresent invention.

As illustrated on FIG. 1, the method for determining a parameter of anoptical equipment according to the invention comprises at least:

-   -   an optical equipment positioning step S1,    -   a portable electronic device positioning step S2, and    -   a parameter determining step S5.

During the optical equipment positioning step S1, an optical equipmentcomprising at least a pair of optical lenses mounted on a spectacleframe is positioned in a first position.

During the portable electronic device positioning step S2, a portableelectronic device comprising at least an image acquisition module, forexample a camera, is positioned in a second position. The secondposition may be determined and/or known relatively to the first positionin which the optical equipment is positioned during step S1.

The optical equipment and the portable electronic device are positionedso as to allow acquiring by the image acquisition module of the portableelectronic device, an image of a distant element seen through at leastpart of the optical lenses of the optical equipment in the firstposition.

According to some embodiment of the invention a specific zone of theoptical lenses may be of interest, such as the optical center for asingle vision lens, or the far and/or near vision zone for a multifocallens. In such case an image of the distant element seen through suchspecific zones of the optical lenses may be sufficient to determineoptical parameters of the optical lenses.

In a preferred embodiment, the optical equipment and the portableelectronic device are positioned so as to allow acquiring an image of adistant element seen through all of the optical lenses of the opticalequipment in the first position. Advantageously, having an image overall the surface of each optical lenses provide more accurate and precisedetermination of the optical parameters of the optical lenses of theoptical equipment.

FIG. 2 illustrates an example in which a pair of spectacles 10 ispositioned between a camera 20 of a portable electronic device at adistance d1 and a screen 30 at a distance d2.

As illustrated in FIG. 2, the pair of spectacles 10 and the camera 20are positioned so that an image of at least part of the screen 30 seenthrough at least part of the optical lenses 12 of the pair of spectaclecan be acquired by the camera 20.

In the sense of the invention, the portable electronic device is anyportable electronic device comprising an image acquisition module, suchas a camera, CMOS or CDD. For example, the portable electronic devicemay be a smartphone, a personal digital assistant, or a tablet computer.

The portable electronic device preferably comprises a memory to storeexecutable computer programs and data and a processor to execute thestored computer program. The portable electronic device may furthercomprise a communication unit to allow the portable electronic device tocommunicate data with distant device. The communication unit may beconfigured either for a wire connection or a wireless connection usingfor example WIFI or Bluetooth® technology.

The wire connection may also by a USB type. The portable electronicdevice may comprise a memory storing data and the data may becommunicated to distant entity using a cable connection.

In order to achieve accurate measurements, it is recommended that duringthe optical equipment positioning step the frame is not positioned inany manner relative to the image acquisition module. Indeed, poorpositioning of the frame may result in significant errors in themeasurement of optical parameters of the optical lenses.

For example, it is desirable that:

-   -   the frame is placed horizontally, adjusting angle Alpha as        represented on FIG. 3,    -   the branches of the spectacle frame are parallel to the optical        axis of the acquisition module in an horizontal plane, adjusting        angle Beta as represented on FIG. 3,    -   the branches of the spectacle frame are parallel to the optical        axis of the acquisition module in a vertical plane, or a slight        angle of about 10° to compensate the pantoscopic angle,        adjusting the angle Gamma as represented on FIG. 3.

To assure a correct position of the optical equipment, the portableelectronic device may comprise a position help module that provides afeedback to the user on how to position the optical equipment. This isparticularly useful when the user needs to hand both the opticalequipment and the electronic device, because positioning may be moredifficult for the user.

The positioning of the frame (Beta, Gamma) can be achieved via a visualaid on a screen, for example the screen of the portable electronicdevice to ensure an accurate measurement.

For example, the frame is shot, and the portable electronic devicecomprises an image processing unit or communicates data with a distantentity comprising the image processing unit. The image processing unitis capable of checking that angle Beta is close to 0 by checking thesymmetry of right sides/left of the frame.

If the symmetry is poor, it is indicated on the screen how to orient themount to correct this.

In a similar manner, it can be checked by image processing that thesides of the frame are parallel to the optical axis of the acquisitionmodule: the image of the branches should in this case be contained on ahorizontal line.

The angle alpha of the frame can be determined by image processing,allowing by rotating the image by image processing repositioning theframe so as to have the angle alpha close to 0.

The distant element whose image through at least part of the opticallenses is to be acquired using the portable electronic device may be apattern such as square grid, equally spaced dots, letters from a book ora newspaper, symbols etc. . . . positioned at a given distance of theoptical equipment or an element far enough to be considered at infinity.

For example, the distant element may be an element of the environment(tree, building, wallpaper, printed book . . . ). In this case thedistant element is preferably immobile, with sufficient contrast, to getmost accurate measurements.

In this respect the portable electronic device may comprise a distantelement quality indicator which authorize or not the measure accordingto the characteristics of distant element seen through the opticallenses, for example element contrast indicator and/or number ofelements. Preferably, the distant element is located at a distancegreater than 4 m so as to be considered at infinity.

As illustrated in FIG. 1, the method of the invention may comprise apattern positioning step S3.

During the pattern positioning step S3, a pattern is positioned in athird position relative to the optical equipment so as to allow theportable electronic device in the second position to acquire an image ofthe pattern seen through at least part of the optical lenses of theoptical equipment in the first position.

Preferably, the third position is determined and/or known relatively tothe first and/or second position.

The pattern can be displayed on a screen for example a computer monitoror a smart phone. The pattern may also be a printed pattern on astandard sheet of paper, or text printed on a piece of paper.

The display of the pattern and the acquisition of the images can beperformed by only one device (for example, a smartphone or a laptop) byusing a mirror 50 as illustrated on FIG. 8.

The pattern may be a dot matrix, colored or uncolored, a grid. Thepattern may be movable to cover a greater portion of the optical lenses.

Preferably, the features of the pattern have a width of at least threetimes the resolution of the acquisition module in order to have anaccurate measurement of the position of the different features.

The physical size of the pattern need to be known, and this size can beknown from a size value input from the user, from a measurement using aphoto of both the pattern and an known size element, such as a creditcard, or from normalized value of the pattern, for example thenormalized size of a sheet of paper having 5 mm square grid used as apattern.

The method of the invention may further comprise a position determiningstep S4. During the position determining step S4, the distance and therelative orientation of the image acquisition module of the portableelectronic device and the optical equipment are determined.

According to an embodiment of the invention, the distance and relativeorientation of the image acquisition module of the portable electronicdevice and the optical equipment are determined using at least measuringmeans of the portable electronic device.

Indeed, the portable electronic may be equipped with measuring meanssuch a stereo or 3D camera, telemeter that may be used to determine thedistance and orientation of the optical equipment and/or the distantelement.

According to an embodiment of the invention, the distance and relativeorientation of the image acquisition module of the portable electronicdevice and the optical equipment are determined using at least measuringmeans including a printed sheet having specific printed features.

Typically, the distant element is a pattern of known dimension, such asa standard sheet having a standard dimension grid printed.

According to an embodiment of the invention, the distance and relativeorientation of the image acquisition module of the portable electronicdevice and the optical equipment are determined using a known sizeelement positioned at the second and third positions. For example, acredit card or a known coin may be positioned next to the opticalequipment and the distant element to provide a reference element used todetermine the distances and relative orientations.

During the parameter determining step S5, at least one optical parameterof the optical equipment is determined. The optical parameter isdetermined based on the image of a distant element seen through at leastpart of the optical lenses of the optical equipment in the firstposition.

The optical parameter may be determined using a processor included inthe portable electronic device or in a distant entity communicating withthe portable electronic device via communication means.

For example, the optical parameter is determined by comparing thepattern with the image of the pattern seen through at least part of theoptical lenses of the optical equipment in the first position. Thepattern compared to the image of the pattern seen through the opticallenses, may either be an image of the pattern taken by the acquisitionmodule without the optical equipment, or the image of the pattern thatappears around the optical equipment or corresponds to a known pattern.

The optical parameter may be determining by analyzing the characteristicof the pattern seen through the optical lenses.

For example if one uses a dot matrix, the characteristic size may be thedistance between 2 points, if a grid is used, the characteristic sizemay be the size of a square or the characteristic of the pattern may bethe positions of the 4 corners, etc. . . .

This size is measured (in pixels) by analysis of the image at sub-pixelresolutions.

For example, in the case of a dot matrix, it is determined the center ofgravity of each dot matrix at resolutions of 1/100 pixels.

One then obtains T1 (x, y) the size feature of the lens at a point (x,y) of the optical lens.

The size feature of the pattern T0 (x, y) may be measured in the absenceof the optical equipment, for example by removing the optical equipment,or by measuring the size feature around the optical lenses or by simplyknowing the size feature of the pattern.

One may determine the magnification G (x, y)=T1 (x, y)/T0 (x, y) of theoptical lenses. This magnification G may differ versus orientation, forexample G may be different for horizontal axis and vertical axis whencylindrical power exist. The following example are given for lenseshaving no cylindrical power, but one can easily generalize this tolenses having cylinder by application to the following formula todifferent orientation.

The optical parameter of the optical equipment comprises parametersselected in the list consisting of:

-   -   the optical power in a visual reference zone of the optical        lenses,    -   the optical cylinder in a visual reference zone of the optical        lenses,    -   the optical cylinder axis in a visual reference zone of the        optical lenses,    -   the prism in a visual reference zone of the optical lenses,    -   the type of optical design of the optical lenses, such as the        distribution of optical power on the surface of the optical        lens.

The optical power in a visual reference zone of the optical lens may bedetermining from the magnification G (x, y), and distance d1 between theoptical equipment and the acquisition module and distance d2 between theoptical equipment and the distant element, for example the pattern.

For example, S(x,y)=(1−1/G(x,y))*(d1+d2)/(d1*d2)

with S the value of the spherical power, this value can be determinedlocally, it is possible to check if the optical lenses are single vision(G (x, y) constant) or multifocal lenses.

Alternatively, it is also possible to determine the optical lens powerby ray tracing. In this case, it is determined by optimization theoptical lens generates the same strain as observed by the camera.

It is also possible to determine the optical center of the lens, or moregenerally the points of zero horizontal prismatic deviation.

Knowledge of these reference points makes it possible to determine howthe lenses are centered in relation to the frame (these points shouldcorrespond to an alignment with the pupils of the eyes), and may allowcontrolling lens centered in the same manner as existing equipment.

For example, in addition or instead of determining the magnification ofthe pattern but their movement, and in particular one determined pointsof the optical lens for which the horizontal displacements are zero.

For example, in the case of a pattern made up of a grid of points, onemay determine the displacement of each point with/without the opticalequipment, and that it is determined for which the horizontal movementis zero (possibly by interpolation).

The method of the invention may further comprise a dimension determiningstep S0 during which at least one dimension of the optical equipment isdetermined.

An example of implementation of the dimension determining step S0 may bedescribed with reference to FIG. 10.

In the example of FIG. 10, the optical equipment is a spectacle frame 10comprising optical lenses and the dimensions to be determined are thetemple length L_(T) and the frame width L_(F).

The dimension determining step may comprise putting the spectacle frame10 on a pattern whose dimensions are known, for example a calibratedscreen or paper whose format is known or paper with elements of knownsize. A photo of the spectacle frame using a portable electronic devicemay then be taken and then image processing done to automaticallydetermine the temple length L_(T) and the frame width L_(F).

The pattern used may advantageously be design to provide a high contrastlevel between the pattern and the optical equipment so as to facilitateimage processing.

In case of the use of a laptop screen, the user may need to put anobject whose dimensions are known, for example a credit card or asmartphone on the screen.

As illustrated on FIG. 11, a rectangle whose size is known in pixels isdisplayed on the screen. By taking a picture of the screen and theobject of known dimension, such as the card or by adjusting the size ofthe rectangle to the size of the card, it is possible to have therelation between a pixel and 1 mm (pixel size). The pixel size beingknown, the pattern size is thus also known.

During the optical equipment positioning step S1, the optical equipmentmay be positioned relative to a pattern by putting the extremity of theoptical equipment, for example the frame temple, in contact with thepattern displayed on a screen or printed-out on a paper for example.Such positioning is illustrated on FIGS. 12A and 12B.

During this step, the position and orientation of the optical equipmentcan be defined by using patterns and indications on the pattern supportas indicated in FIG. 12B. This enables to help the user to center andtilt the optical equipment as required.

In the example of FIG. 12B, two patterns right and left small rectanglesare used to position the end of the temple of the frame, while a bigsize rectangle is used to position the frame shape for orientation.

During the portable device positioning step S2, the portable electronicdevice may be positioned using the pattern described previously pictureand having the user

-   -   setup the distance d2 between the device and the pattern so that        the spectacle frame is seen completely into the big size        rectangle, and    -   setup the orientation of the frame so that the big rectangle is        seen by the camera of the portable electronic device with four        right angles.

Alternatively, during the portable electronic device positioning stepS2, the portable electronic device may be positioned using a layoutillustrated on FIG. 13 with four squares available on the portableelectronic device screen and having the user superpose the squares withfour squares available on the pattern support.

Advantageously, with this solution it is possible to automate the imagetaking step if the function is implementation through a nativeapplication for example.

As illustrated on FIG. 14, using the image taken during the parameterdetermining step S5 and the geometrical dimensions determined during thegeometrical dimension step S0, it is possible to determine the distanceposition between the electronic device and the optical equipment usingperspective effect having:

$\frac{L_{F\; 2}}{d\; 2} = \frac{L_{F}}{{d\; 2} - L_{T}}$

It is possible to improve the dimension determining step performance inorder to correct some not negligible perspective effects during thedimension determining step S0. Indeed, as illustrated on FIGS. 15 and16, the frame is not perfectly in the same plane as the pattern, due toframe height H_(F).

Correction of the perspective effects may be done by taking anadditional picture of the optical equipment with the lens in contactwith the pattern support used in the dimension determining step S0, asillustrated on FIG. 17.

Correction of the perspective effects may further comprise using imagestaken during steps S0 and S5 and implementing an iterative calculationtaking into account the ratio L_(F)/H_(F)=L_(FV)/H_(FV) measured on thepicture from the step S5 and illustrated on FIG. 18.

As illustrated on FIG. 1, the method of the invention may furthercomprise a fitting parameter determining step S6.

During which at least one fitting parameter of the optical lenses in thespectacle frame is determined based on an image of the spectacle frameacquired by the portable electronic device and the image of a distantelement seen through at least part of the optical lenses of the opticalequipment in the first position.

Typically, the fitting parameter is determined based on the position ofa reference point of the optical lenses relative to the spectacle frame.

As illustrated on FIG. 4, the invention further relates to a device 40for determining at least a parameter of an optical equipment 10comprising a pair of optical lenses 12 mounted on a spectacle frame.

The device may comprise a receiving element 42 and an acquisitionreceiving element 44.

The receiving element 42 is configured to physically receive an opticalequipment 10 in at least a first predetermined position. The deviceaccording to the invention may comprise a plurality of receivingelements 42 or the receiving element 42 may be moved between knownpositions.

The acquisition receiving element 44 is configured to physically receivea portable electronic device having an image acquisition module in atleast a second predetermined position relative to the optical equipmentreceived by the receiving element so as to acquire an image of a distantelement seen through at least part of the optical lenses of the opticalequipment received by the receiving element.

Advantageously, the use of such a device helps assuring an accurate andcontrolled position and orientation between the acquisition module andthe optical equipment.

As further illustrated on FIG. 4, the device according to the inventionmay further comprise a predetermined pattern 30 to be used as saiddistant element.

Advantageously, having a predetermined pattern in the device of theinvention provides more controlled conditions for determining parametersof the optical equipment. Preferably, the predetermined pattern is in athird predetermined position relative to the first and secondpredetermined positions.

The device of the invention may also comprise a transparent side so asto allow using a distant element of the environment as distant elementor a printed pattern.

The device according to the invention may comprise means for determiningthe position of the distant element relative to the first and/or secondpredetermined positions.

As illustrated on FIG. 9, the device according to the invention mayfurther comprising a light reflecting element 50 configured to reflect apattern displayed on a screen of the portable electronic device 20 so asto provide a distant element to be acquired by the portable electronicdevice through at least part of the optical lenses of the opticalequipment 10 received by the receiving element. This reflecting elementmay be in the form of a standard mirror, and the user may place theequipment in contact with the mirror. The display is then used todisplay the pattern, and the camera (at the same side than the display)is used to take an image of the pattern seen through the equipment. Inthis case, the distance d1 and d2 are the same, and the pattern will bedeformed by the lens twice, since a reflection occurs. The powermeasurement will be twice the real lens power.

The device according to the invention may be provided to the person as atemplate. For example, the person may download a template to be printed.

The template may be specifically adapted to the type of portableelectronic device and may be directly printable on one or a plurality ofstandard sheets.

FIG. 5 is an example of template comprising reference to help the personposition the portable electronic device and the optical equipment.

The template illustrated on FIG. 5 further comprises a known pattern 30that may be used to determine the relative position of the opticallenses with the portable electronic device and the pattern.

In a first step, the person does not touch anything and just put hissmartphone at the location indicated on the template, taking care toplace the rear camera at the location indicated on the template. Theperson also places the front of equipment at a known location indicatedon the template, and the pattern at a known location. This pattern canbe a part of the template itself, for example a part of a sheet of paperhaving square grid and 90° folded at the pattern location.

As an alternative, the equipment location may not be indicated, and thebranches of the frame may be measured first by taking a photo or byusing the known size of the pattern 30, and then the end of the 2branches may be in contact with the pattern so that the position of thefront of the equipment is known.

Another alternative consists of delivering a template composed of 3parts:

-   -   a first part similar to the template described in FIG. 5 and        being the base of the device    -   a second part which can be clicked to the side of the base near        the frame position and which deliver the pattern    -   a third part which can be clicked to the opposite side of the        base near and which receives the electronic device.

This first part is obtained by folding a paper according to specificinstructions to ensure the best maintaining of the device at a knowndistance of the pattern. This part can be defined specifically for eachtype of electronic device.

Other combination of alternatives than the examples described previouslyare possible.

For example, the distances may be determined thanks to images of a knownobject 50, such as a credit card, placed in the frame and pattern plans,and thanks to the knowledge of camera focal value as illustrated on FIG.9.

In a second step, the frame and the smartphone being well positioned,images are taken of the grid of the pattern deformed through the opticallenses. The length of the branches of the frame (previously measured)being known and the smartphone position being fixed, the distance d1 andd2 are known without the need to know the characteristics of the cameraof the smartphone.

Images of maximum stability are selected (optimal sharpness) tocompensate the tremor of the person.

The image acquisition can be controlled completely independently by anautomatic adjustment of focus and by using a timer to trigger thephoto-taking without undergoing any shaking of the user.

In a third step the size of the grid seen through the optical lenses arecompared to the known size of the grid to determine the magnification G(x, y) at different points of the optical lenses.

Optical features of the optical lenses may then be determined.

The device may of course be adapted to the different type of portableelectronic devices and/or spectacle frames.

The invention also relates to a method for ordering a new opticalequipment for a user of a first optical equipment.

As illustrated on FIG. 6, the ordering method of the invention maycomprise:

-   -   an optical equipment positioning step S10, during which the        first optical equipment comprising a first pair of optical        lenses mounted on a first spectacle frame is positioned in a        first position,    -   a portable electronic device positioning step 11, during which a        portable electronic device comprising an image acquisition        module is positioned in a second position so as to acquire an        image of a distant element seen through at least part of the        optical lenses of the first optical equipment in the first        position,    -   an acquisition step S12, during which at least one image of the        distant element seen through at least part of the optical lenses        of the first optical equipment is acquired,    -   a position adjustment step S13, during which the relative        position of the portable electronic device and the first optical        equipment is adjusted based on an identification of at least        part of the optical equipment and/or the portable electronic        device,    -   an ordering step S15, during which an order request for a new        optical equipment is sent to a distant entity, the order request        comprising the at least one image acquired by the portable        electronic device and new optical equipment identification data.

The ordering method of the invention may further comprise a parameterdetermining step S14, during which at least one optical parameter of theoptical equipment is determined based on the image of a distant elementseen through at least part of the optical lenses of the opticalequipment in the first position.

So as to increase the accrual of the measurements and the overallsatisfaction of the user, the ordering method may comprise a deviceproviding step during which a device according to the invention isprovided to position the first optical equipment and a portableelectronic device.

As illustrated on FIG. 7, the invention further relates to a method forproviding optical equipment for a person. The providing methodcomprises:

-   -   an order receiving step S20 during which an order request        generated by a method according to the invention and comprising        at least an image of a predetermined element seen through at        least part of the optical lenses of the first optical equipment        of the person is received,    -   a parameter determining step S21 during which at least one        optical parameter of the optical equipment is determined based        on the at least one received image,    -   an optical equipment providing step S22 during which a new        optical equipment is provided to the person based on the at        least one optical parameter determined during the parameter        determining step.

The invention has been described above with the aid of embodimentswithout limitation of the general inventive concept; in particular themounted sensing device is not limited to a head mounted device.

Many further modifications and variations will suggest themselves tothose skilled in the art upon making reference to the foregoingillustrative embodiments, which are given by way of example only andwhich are not intended to limit the scope of the invention, that beingdetermined solely by the appended claims.

In the claims, the word “comprising” does not exclude other elements orsteps, and the indefinite article “a” or “an” does not exclude aplurality. The mere fact that different features are recited in mutuallydifferent dependent claims does not indicate that a combination of thesefeatures cannot be advantageously used. Any reference signs in theclaims should not be construed as limiting the scope of the invention.

1-19. (canceled)
 20. A method for determining a parameter of an opticalequipment, the method comprising: an optical equipment positioning,during which an optical equipment comprising a pair of optical lensesmounted on a spectacle frame is positioned in a first position; aportable electronic device positioning, during which a portableelectronic device comprising an image acquisition module is positionedin a second position determined and/or known relatively to the firstposition to acquire an image of a distant element seen through at leastpart of the optical lenses of the optical equipment in the firstposition; a parameter determining, during which at least one opticalparameter of the optical equipment is determined based on the image of adistant element seen through at least part of the optical lenses of theoptical equipment in the first position.
 21. The method according toclaim 20, further comprising a pattern positioning during which apattern is positioned in a third position relative to the opticalequipment to allow the portable electronic device in the second positionto acquire an image of the pattern seen through at least part of theoptical lenses of the optical equipment in the first position.
 22. Themethod according to claim 21, wherein the third position is determinedand/or known relatively to the first and/or second position.
 23. Themethod according to claim 21, wherein the optical parameter isdetermined by comparing the pattern with the image of the pattern seenthrough at least part of the optical lenses of the optical equipment inthe first position.
 24. The method according to claim 20, furthercomprising a position determining during which the distance and therelative orientation of the image acquisition module of the portableelectronic device and the optical equipment are determined.
 25. Themethod according to claim 24, wherein the distance and relativeorientation of the image acquisition module of the portable electronicdevice and the optical equipment are determined using at least measuringmeans of the portable electronic device.
 26. The method according toclaim 24, wherein the distance and relative orientation of the imageacquisition module of the portable electronic device and the opticalequipment are determined using at least measuring means including aprinted sheet having specific printed features.
 27. The method accordingto claim 24, wherein the distance and relative orientation of the imageacquisition module of the portable electronic device and the opticalequipment are determined using a known size element positioned at thesecond and/or third positions.
 28. The method according to claim 20,wherein the optical parameter of the optical equipment comprisesparameters selected from: the optical power in a visual reference zoneof the optical lenses, the optical cylinder in a visual reference zoneof the optical lenses, the optical cylinder axis in a visual referencezone of the optical lenses, the prism in a visual reference zone of theoptical lenses, the type of optical design of the optical lenses. 29.The method according to claim 20, further comprising: a fittingparameter determining during which at least one fitting parameter of theoptical lenses in the spectacle frame is determined based on an image ofthe spectacle frame acquired by the portable electronic device and theimage of a distant element seen through at least part of the opticallenses of the optical equipment in the first position, wherein thefitting parameter is determined based on the position of a referencepoint of the optical lenses relative to the spectacle frame.
 30. Adevice for determining at least a parameter of an optical equipmentcomprising a pair of optical lenses mounted on a spectacle frame, thedevice comprising: a receiving element configured to physically receivethe optical equipment in at least a first predetermined position; anacquisition receiving element configured to physically receive aportable electronic device having an image acquisition module in atleast a second predetermined position relative to the optical equipmentreceived by the receiving element to acquire an image of a distantelement seen through at least part of the optical lenses of the opticalequipment received by the receiving element.
 31. The device according toclaim 30, further comprising at least one predetermined pattern to beused as the distant element.
 32. The device according to claim 31,wherein the predetermined pattern is in at least a third predeterminedposition relative to the first and second predetermined positions. 33.The device according to claim 30, further comprising means fordetermining the position of the distant element relative to the firstand/or second predetermined positions.
 34. The device according to claim30, further comprising a light reflecting element configured to reflecta pattern displayed on a screen of the portable electronic device toprovide a distant element to be acquired by the portable electronicdevice through at least part of the optical lenses of the opticalequipment received by the receiving element, wherein the device isconfigured so that the portable electronic device acquires an image ofthe pattern deformed twice by the optical equipment, and the portableelectronic device is selected from a smartphone, a personal digitalassistant, or a tablet computer.
 35. A method for ordering a new opticalequipment for a user of a first optical equipment, the methodcomprising: an optical equipment positioning, during which the firstoptical equipment comprising a first pair of optical lenses mounted on afirst spectacle frame is positioned in a first position; a portableelectronic device positioning, during which a portable electronic devicecomprising an image acquisition module is positioned in a secondposition to acquire an image of a distant element seen through at leastpart of the optical lenses of the first optical equipment in the firstposition; an acquisition during which at least one image of the distantelement seen through at least part of the optical lenses of the firstoptical equipment is acquired; a position adjustment during which therelative position of the portable electronic device and the firstoptical equipment is adjusted based on an identification of at leastpart of the optical equipment and/or the portable electronic device; anordering during which an order request for a new optical equipment issent to a distant entity, the order request comprising the at least oneimage acquired by the portable electronic device and new opticalequipment identification data.
 36. The method according to claim 35,further comprising a parameter determining, during which at least oneoptical parameter of the optical equipment is determined based on theimage of a distant element seen through at least part of the opticallenses of the optical equipment in the first position.
 37. The methodaccording to claim 35, further comprising a device providing duringwhich a device is provided to position the first optical equipment and aportable electronic device.
 38. A method for providing optical equipmentfor a person, the method comprising: an order receiving during which anorder request generated by a method according to claim 35 and comprisingat least an image of a predetermined element seen through at least partof the optical lenses of the first optical equipment of the person isreceived; a parameter determining during which at least one opticalparameter of the optical equipment is determined based on the at leastone received image; an optical equipment providing during which a newoptical equipment is provided to the person based on the at least oneoptical parameter determined during the parameter determining.